How to send vector of string to MATLAB compiled DLLs, using mwArray?

Page at mwArray class describes about constructor to create a mwArray cell of array of string as: mwArray(mwSize num_strings, const char** str).

I have a vector of string which has been dynamically populated. I have converted vector<string> to char** and trying to make mwArray with this data. However, the constructor signature has const char**, so it is failing to convert char** to const char**

How else a vector of string can be set to a mwArray cell and sent to MATLAB DLLs?

Answer 1

[Guillaume]

Yes, C++ will not let you convert T** to const T**. While you probably could use an explicit cast, the best solution is to change your conversion from vector<string> so that it outputs directly const char**.

You must actually have purposefully cast away the constness of const char* returned by string.c_str, so don't do that!

std::vector<std::string> strings { "one", "two", "three"};
std::vector<const char*> cstrings;
for (size_t i = 0; i < strings.size(); ++i)
    cstrings.push_back(strings[i].c_str());  \\convert string to const char*
mwArray mstrings(cstrings.size(), cstrings.data());  \\cstrings.data() is const char**